Kristen Stewart - Kristen Stewart Affair Went On For Months, Sanders' Brother-in-law Claims

News that the alleged 'momentary indiscretion' between Kristen Stewart and RUPERT SANDERS was much more than that, as his Brother-in-law has come forth to claim that the affair went on for months, after he spoke to The People magazine.

The Snow White and the Huntsman director and star are believed, by a number of Sander's wife's family, to have begun their fling well into the filming of the fairytale-twist movie.

Sanders' actress/model wife Liberty Ross, who plays Kristen's mother in the Snow White movie, believes the fling started during filming last year and carried on until 2012. She has also mentioned how she saw the pair looking admirably at one-another during the premier of the film, further fuelling her suspicions. She has since gone on to forgive her husband for his part in the affair, however Robert Pattinson may not be so forgiving.

Tension between the Twilight-lovers emerged in 2009 when Robert became close to Australian actress Emilie De Ravin while filming Remember Me. They stayed friends and remain in touch to this day, apparently, and he was a shoulder to cry on when her marriage to actor JOSH JANOWI hit the rocks.

Liberty's younger brother Leopold insisted: "It was from the last half of filming and all through post-production, clear into last week."